In an exhaust gas purification apparatus in which a catalyst for exhaust gas purification is arranged in an exhaust passage of an internal combustion engine, there has been known a technology in which temperature raising processing to raise the temperature of the catalyst to an activation temperature thereof is started at the time of the start of the internal combustion engine. In addition, there has also been proposed a technology in which in cases where the state of a catalyst after the lapse of a predetermined period of time from the start of an internal combustion engine has not yet reached a desired warm-up state, a control parameter in temperature raising processing is changed so that the temperature of the catalyst goes up much more easily (for example, refer to a first patent literature).
Moreover, a second patent literature describes a technology that in a system in which for a predetermined period of time from the start of an internal combustion engine, exhaust gas reduction control is executed for reducing or decreasing an amount of hydrocarbon (HC) discharged from the internal combustion engine, and after the lapse of the predetermined period of time, catalyst warming-up promotion control is executed for causing the temperature of an exhaust gas purification catalyst to go up, the length of the predetermined period of time is changed according to the degree of deterioration of the catalyst.